/**
 * @license Copyright (c) 2003-2023, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */
/**
 * @module image/autoimage
 */
import { Plugin } from 'ckeditor5/src/core';
import { Clipboard } from 'ckeditor5/src/clipboard';
import { LivePosition, LiveRange } from 'ckeditor5/src/engine';
import { Undo } from 'ckeditor5/src/undo';
import { Delete } from 'ckeditor5/src/typing';
import { global } from 'ckeditor5/src/utils';
import ImageUtils from './imageutils';
// Implements the pattern: http(s)://(www.)example.com/path/to/resource.ext?query=params&maybe=too.
const IMAGE_URL_REGEXP = new RegExp(String(/^(http(s)?:\/\/)?[\w-]+\.[\w.~:/[\]@!$&'()*+,;=%-]+/.source +
    /\.(jpg|jpeg|png|gif|ico|webp|JPG|JPEG|PNG|GIF|ICO|WEBP)/.source +
    /(\?[\w.~:/[\]@!$&'()*+,;=%-]*)?/.source +
    /(#[\w.~:/[\]@!$&'()*+,;=%-]*)?$/.source));
/**
 * The auto-image plugin. It recognizes image links in the pasted content and embeds
 * them shortly after they are injected into the document.
 */
export default class AutoImage extends Plugin {
    /**
     * @inheritDoc
     */
    static get requires() {
        return [Clipboard, ImageUtils, Undo, Delete];
    }
    /**
     * @inheritDoc
     */
    static get pluginName() {
        return 'AutoImage';
    }
    /**
     * @inheritDoc
     */
    constructor(editor) {
        super(editor);
        this._timeoutId = null;
        this._positionToInsert = null;
    }
    /**
     * @inheritDoc
     */
    init() {
        const editor = this.editor;
        const modelDocument = editor.model.document;
        const clipboardPipeline = editor.plugins.get('ClipboardPipeline');
        // We need to listen on `Clipboard#inputTransformation` because we need to save positions of selection.
        // After pasting, the content between those positions will be checked for a URL that could be transformed
        // into an image.
        this.listenTo(clipboardPipeline, 'inputTransformation', () => {
            const firstRange = modelDocument.selection.getFirstRange();
            const leftLivePosition = LivePosition.fromPosition(firstRange.start);
            leftLivePosition.stickiness = 'toPrevious';
            const rightLivePosition = LivePosition.fromPosition(firstRange.end);
            rightLivePosition.stickiness = 'toNext';
            modelDocument.once('change:data', () => {
                this._embedImageBetweenPositions(leftLivePosition, rightLivePosition);
                leftLivePosition.detach();
                rightLivePosition.detach();
            }, { priority: 'high' });
        });
        editor.commands.get('undo').on('execute', () => {
            if (this._timeoutId) {
                global.window.clearTimeout(this._timeoutId);
                this._positionToInsert.detach();
                this._timeoutId = null;
                this._positionToInsert = null;
            }
        }, { priority: 'high' });
    }
    /**
     * Analyzes the part of the document between provided positions in search for a URL representing an image.
     * When the URL is found, it is automatically converted into an image.
     *
     * @param leftPosition Left position of the selection.
     * @param rightPosition Right position of the selection.
     */
    _embedImageBetweenPositions(leftPosition, rightPosition) {
        const editor = this.editor;
        // TODO: Use a marker instead of LiveRange & LivePositions.
        const urlRange = new LiveRange(leftPosition, rightPosition);
        const walker = urlRange.getWalker({ ignoreElementEnd: true });
        const selectionAttributes = Object.fromEntries(editor.model.document.selection.getAttributes());
        const imageUtils = this.editor.plugins.get('ImageUtils');
        let src = '';
        for (const node of walker) {
            if (node.item.is('$textProxy')) {
                src += node.item.data;
            }
        }
        src = src.trim();
        // If the URL does not match the image URL regexp, let's skip that.
        if (!src.match(IMAGE_URL_REGEXP)) {
            urlRange.detach();
            return;
        }
        // Position will not be available in the `setTimeout` function so let's clone it.
        this._positionToInsert = LivePosition.fromPosition(leftPosition);
        // This action mustn't be executed if undo was called between pasting and auto-embedding.
        this._timeoutId = setTimeout(() => {
            // Do nothing if image element cannot be inserted at the current position.
            // See https://github.com/ckeditor/ckeditor5/issues/2763.
            // Condition must be checked after timeout - pasting may take place on an element, replacing it. The final position matters.
            const imageCommand = editor.commands.get('insertImage');
            if (!imageCommand.isEnabled) {
                urlRange.detach();
                return;
            }
            editor.model.change(writer => {
                this._timeoutId = null;
                writer.remove(urlRange);
                urlRange.detach();
                let insertionPosition;
                // Check if the position where the element should be inserted is still valid.
                // Otherwise leave it as undefined to use the logic of insertImage().
                if (this._positionToInsert.root.rootName !== '$graveyard') {
                    insertionPosition = this._positionToInsert.toPosition();
                }
                imageUtils.insertImage({ ...selectionAttributes, src }, insertionPosition);
                this._positionToInsert.detach();
                this._positionToInsert = null;
            });
            const deletePlugin = editor.plugins.get('Delete');
            deletePlugin.requestUndoOnBackspace();
        }, 100);
    }
}
